I think you're missing a vital point here. If you have the Thomson stem you can just completely remove the front plate and the sweep/size/grip whatever about the bar is completely irrelevant. That way you can make choices based on fit and comfort, not on some strange limiting idea that won't end up saving time at all. You won't even need a carbon bar with this set-up because you could just wrap up the entire bar. Or, you could just use gloves and the warmth element won't matter.

In response to the QR again, I can assure you that the bike did not come designed with QRs intended to be used with carbon parts. It might work fine for you so far, but when it does fail it will either be a crack that will make your expensive carbon bars unsafe to use, or it will just snap. It may never happen, but when there is a very easy way to do things as it is intended, why not follow the instructions? I can't imagine the difference between screwing two bolts and doing a QR is more than a minute or two. I can't even imagine how you would get a QR to work with a Thomson stem, let alone any other modern oversized stem. If you have a method, I'd love to see it.

You proposal of cutting down road bars is equally as weird, you're going to have a very narrow bar that will likely have cable grooves and other "features" and even after that will likely not match your perfectly straight requirement. A 3 degree sweep bar cut to the width you'd get from road bars would have such a small sweep it wouldn't even be noticeable.

Just because you have devised an overcomplicated and convoluted solution to a very easy problem doesn't mean you need to continue making it difficult when easier solutions are presented to you.

But, you mention it uses a quill stem...so will any of this even be possible? You'll end up running a quill extender to a quill to threadless adaptor, to a threadless stem, to carbon bars? And, finally with a QR on that? Seems like if weight is a concern there's lots of other areas you could drop it.